The field of the invention is writing or marking instruments and the invention relates more particularly to a cosmetic pencil having means for advancing the cosmetic mass outwardly therefrom.
Instruments for holding and ejecting writing or marking materials have been known for many years with mechanical pencils being, perhaps, the most widely used application of such technology. The use of a gripping disk positioned about a central push rod is likewise well known, and one early example is shown in U.S. Pat. No. 1,447,677 to Lindberg which utilizes a pair of disks which have a central opening which will grip a central push rod when the disk is moved from a right angle with respect to the push rod.
Makeup sticks have been inserted in pencil-like devices for many years. One early example being U.S. Pat. No. 2,142,312 to Heinz. Typically, however, most cosmetic pencils in common use are either provided in a wooden pencil sheath which is sharpened in the manner of the common lead pencil or with sharpenable crayons which are advanced with a threaded sleeve surrounding a threaded central push member such as shown in U.S. Pat. No. 3,768,915 to Spatz. It is important for many cosmetic applications that the cosmetic pencil have a relatively fine point so that the cosmetic can be applied to the exact area or line desired. For that reason, many cosmetic pencils provide some sharpening means such as shown in the above-referred Spatz patent. A major problem with many cosmetic pencils such as those used for eyeliner, is the lack of structural integrity of the cosmetic mass. The softness of the mass creates a far greater problem than the common rigid lead of a mechanical pencil and some form of sheathing is generally necessary to strengthen the mass. A marking element showing a sheath is disclosed in U.S. Pat. No. Re. 25,741 to Smith. It is desirable, however, that the marking element be very thin so that no sharpening is necessary and efforts to support and control a soft mass in a thin crayon remains an unfilled need. Attempts to provide an advanceable mass usually results in customer dissatisfaction because of the user's tendency to advance the mass too far causing the tip to break off.